In an electrophotographic image forming apparatus, a toner remaining amount detection apparatus for measuring the remaining amount of toner contained in a toner container may be provided. There are various methods used in the toner remaining amount detection apparatuses. For example, there is a light transmission type toner remaining amount detection method as described in PTL 1. The light transmission type toner remaining amount detection method is a method in which detection light is transmitted through a toner container and the remaining amount of toner contained in the toner container is detected by using transmission time of the detection light.
In PTL 1, a stirring member rotates in the toner container, so that the toner is stirred. The transmission time of the detection light is measured for each rotation cycle of the stirring member. When a large amount of toner is contained in the toner container, the detection light is not transmitted through the container, and as the toner is consumed, the detection light is increasingly transmitted through the container. Therefore, the remaining amount of toner is detected by using a phenomenon that a time period in which the detection light is detected increases as the toner is consumed.